Cheap foundation

I currently use benefit foundation and have, in the past, used Urban Decay, Clinique, Lancôme, the lot really. However, I'm trying to cut back and can't really justify spending £25-30 on foundation. Which cheaper brands are any good?

Revlon colour stay is fantastic but it brought me out in cystic acne which is a common complaint (I've since discovered!) so definitely worth a try but if you start getting spots that could be the culprit.

no joke, my eldest dd bought some Natural collection shine away for £1.99, and i tried some, and despite me having much more aged skin (dry, big pores etc...) it's worked so well mixed with a bit of my Bb cream.